overclocking

I think your confusing volts with the memory divider or htt multi. At 250 fsb you need to drop the htt multi to 3.
 
hi i have overclocked my AMD ATHLON 64 3200+ to 2550MHZ (is this a good improvement) and i was wondering if there is room for more?
i put the mem clock value to 166MHZ and the processor frequency multiplier to 4x and the cpu frequency is at 255.
i did read (i think it was in this thread) that if i go over 250 i should change the processor frequency multiplier to 3x but i can mint will only go as low as 4x (but it will go higher)
thanks for reading :D
 
Keep going until you want to stop or until either temps or volts get too high.
Your confusing cpu multiplier with htt multiplier. Your cpu multi is set to 10.
If you go over 250 then yes you do need to lower the htt multi to 3.

Is it still passing prime 95?

Keep going in small steps untill it fails prime 95, then raise the volts a tiny bit, check that it passes and then continue to raise the fsb until prime95 fails again.

Probably best to stop once you reach 1.5v, unless the temperature gets too high before then in which case stop sooner.
Make sure you are keeping an eye on cpu temps.
 
Joe42 said:
Keep going until you want to stop or until either temps or volts get too high.
Your confusing cpu multiplier with htt multiplier. Your cpu multi is set to 10.
If you go over 250 then yes you do need to lower the htt multi to 3.

Is it still passing prime 95?

Keep going in small steps untill it fails prime 95, then raise the volts a tiny bit, check that it passes and then continue to raise the fsb until prime95 fails again.

Probably best to stop once you reach 1.5v, unless the temperature gets too high before then in which case stop sooner.
Make sure you are keeping an eye on cpu temps.
Click to expand...

so i shouldnt of raised the cpu multiplier? :confused: and i could find a htt multi anyway. i havnt done a 24hr test on prime 95 yet should? :confused:
 
You cant raise the cpu multi from its stock x10. Keep it at this but you need to lower the HTT/LDT multi to x3 (also known as 600 on some boards).
 
Do 10 minute tests on prime 95 each time you raise the fsb a little.
So for example you might raise the fsb by 10, boot into windows, and if prime 95 passes its first test your ok to continue and if it fails you need to raise the voltage a little.
Only when you have reached the point were the voltage or temperature is getting too high and your happy with your overclock should you run prime95 for 24 hours to make sure its completely stable.
 
i didnt raise the cpu multi but i did raise a thing called processor frequency multiplier (i dont know if this is the same thing as cpu multi) and what does HTT, LDT and FSB stand for? :confused:
thanks :confused: :confused: :confused: :confused:
 
i have just had a look at "system" (in the control panel) and it said i had 1.02GHZ (on a AMD ATHLON 64 3200+) but i then checked on CPU-Z on the main page and on core speed it said 2550MHZ (2.55GHZ). so i went in the bios and put everything i had changed to auto or back to what it was on. So when windows booted up i looked in the "system" (expecting it to say 2.0GHZ) and it said 801MHZ, so i went into CPU-Z and checked "core speed" and it said 2000MHZ.
so why is CPU-Z and "system" showing different speeds?? :confused: :confused: :confused: :confused: :confused:

(i personnally dont think it is running at 800MHZ it feels as though its running faster)
thanks
 
No idea why it would say 800mhz unless you have cool n quiet enabled. Check its disabled in the bios.

lets clear a few things up. Sorry its such a long post ;)


Fsb = front side bus, although the Athlon 64 does not have a front side bus so the fsb itself does nothing, but it is multiplied up or divided down for each component to operate at a speed derived from it.

Htt/LDT = hypertransport or Lightning Data Transport which is the old name for it that some boards still use. It is what the Athlon 64 uses to communicate between the processor and the chipset, and it needs to be kept below 1000mhz. Its speed is derived from the fsb, and it has a multiplier. Normally the multiplier is 5 and 5 x 200 = 1000mhz. As you raise the fsb you must lower the multi to 4 and then 3 to keep it below 1000mhz.


Cpu multiplier = The multiplier that derives the cpu frequency from the fsb. Yours is 10 i believe, so 10 x 200 = 2000mhz. It can only go down except on expensive fx processors where it can be raised. You don't normally need to change it from default, i changed mine down to 10 from 11 because its easier to calculate what speed your going to get as you raise the fsb.


The memory can be quite complicated depending on what the boards bios looks like, but again the memory frequnecy is derived from the fsb so when you raise it you must put a divider on the memory to slow it down.
The memory is DDR which means Double Data Rate. So memory at 200mhz is actually running at 400mhz, however some boards report the speed as 200 and some as 400.
Cpuz reports it as 200, so thats the level it must be kept to.

Its an asus board and i think its the same as mine, so you will have an option to 'lock' the memory speed. This enables an automatic divider, and you can then set the speed. Set it to 183 (or whatever it is) and it will then increase that number by half of what you add to your 200mhz fsb.
So you raise the fsb to 250, it will add 25 to 183 = 207. Because you have to keep the memory below 200, you will need to lower the speed to 166. In cpuz you will see under the memory tab what divider its actually using. It may say, for example, 'CPU/15' Which means its dividing the cpu frequency by 15 to get the memory speed. So my cpu is at 2500mhz and the memory is 2500/15 = 166. As i change the cpu speed, the board changes the divider to keep your memory as close to 166 as possible, assuming thats the speed you set it at in the bios.



The process of Overclocking. The traditional method:

-You never normally need to change the cpu multiplier, you must change the htt multi to 4 and then to 3 at 250 fsb to keep it below 1000mhz. You enable the 'lock memory speed' option in the bios, and lower the memory speed to 183. When you increase the fsb by 34 so 234 you will need to lower the memory speed to 166 to prevent it going over 200.

-Raise the fsb by 5. Boot up, run prime95 for one test and see if it passes. If it does, back to the bios, raise by 5 again, repeat until prime95 fails. In prime95 go to options/torture test and select 'small ffts' to run a test that stresses the cpu most.

-Its just failed prime95. You now raise the voltage a little bit, run prime95 again to check it now passes, then continue raising the fsb by small amounts until it fails again, then raise the volts a little etc etc. make sure your keeping the htt below 1000 and the memory below 200 as explained above.

-As your overclocking you need to keep an eye on cpu temps. When either the cpu temps get too high (>55) or the voltage gets too high (>1.55) you must stop. When you have reached this point, you must then run prime95 for several hours to make absolutely sure its stable, and if it fails at any point you need to lower the fsb a bit.

-You can also overclock the memory and htt but thats a job for a other day.


My Method:

I overclock slightly differently to the above.
I prefer to first raise the voltage to the highest lever i want it, so 1.55. Then i'll lower the htt to 3 and the memory to 166 because i know i'm going to be exceeding 250 fsb. Then i raise the fsb by a largish amount such as 20, do one test of prime95, go back to the bios and keep raising the fsb, by smaller amounts as it gets higher, until prime95 fails. Then i run prime95 for several hours to make sure its stable.

Hope you read and absorbed all that, please ask if there anything you don't understand. I recomend you set everything back to auto and start again.
Good luck ;)
 
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^^ That's good stuff there. ^^

Have a careful look at that and as many guide as you can find. You should never blunder into overclocking without knowing what you're doing.

You were saying that you couldn't find the htt multi before. Well, this is the first thing that should be changed when overclocking, so if you can't find it, don't overclock! This will damage your board! I take it you probably have a manual with your board - there will be a step-by-step explanation of the BIOS features (and where to find the HTT Multi) in there.

Take a look at reviews of your mobo using google, as these give decent summaries of how the board OCs and its features.
 
I think his bios is the same as mine, thats why i was specific about the memory settings and the stupid stupid automatic divider thing.

And i think theres a chipset settings section with all the htt stuff in.
You'll find the memory settings in the cpu section and the cpu settings in the jumperfree section of course.

I cannot wait for abit to start making proper boards again...
 
i just oced i put the memory at 166MHZ and the fsb to 250/400, i disabled cool 'n' quiet and booted back up. now "system" and CPU-Z say its running at 2550MHZ (2.55GHZ) thats an increase of 550MHZ thanks a lot guys you have being a real help
thanks again joe :D
 
i just checked in my bios and my cpu is at 50-51oC and i think that is pretty high so i am not going to carry on overclocking until the weather cools down a bit
thanks for the help joe
 
Leave all the overvoltage options disabled and you raise the cpu voltage, not the chipset voltage. Can't remember exactly what its called in the bios...
 
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